The present invention relates to a method and apparatus for warning a following vehicle when a vehicle in front, a leading vehicle, applies its brakes.
DE 43 05 186 C2 (U.S. Pat. No. 5,594,416) discloses a method for reducing the danger of rear end accidents in traffic via a deceleration warning; this document also discloses a deceleration warning system. During a braking process, an integral is formed via the deceleration, and as a result a danger value is calculated in conformity with which the signal aspect or pattern of a brake light is affected. After conclusion of a deceleration, the brake light is not immediately extinguished; rather, the lights thereof fade in conformity with a predetermined function or equation. A characteristic of such integral brake lights is that short, pronounced decelerations of the leading vehicle are only presented after a time delay that is due to the integration; this can lead to dangerous situations if traffic is heavy.
Methods for warning a following vehicle are also known where one or more brake lights of a leading vehicle are illuminated in conformity with the present deceleration, and in particular proportionally to the present deceleration. In this connection, the size of the illuminating surface and/or light intensity thereof can vary in conformity with the present deceleration. Such proportionally controlled brake lights generally extinguish immediately after conclusion of the deceleration. A characteristic of the brake lights that illuminate proportionally to the deceleration is that their signal pattern is very uneven due to the deceleration, which generally rapidly varies during a braking process. Furthermore, they draw considerable attention of the driver of a following vehicle even if the braking of the leading vehicle does not present a great danger, for example during very brief, intense decelerations that do not lead to significant reductions in speed. In contrast, at the conclusion of a lasting deceleration, there is no longer a warning, although the braking vehicle presents a great danger to the following vehicle, which is still driving faster.
It is therefore an object of the present invention to provide a method and an apparatus for warning a following vehicle when a vehicle in front applies its brakes, whereby the aforementioned drawbacks are to be overcome and an effective measure is to be provided for reducing rear end accidents.